High-amperage electrical quick disconnection device

Abstract: A compact high-voltage, high-amperage quick disconnection device for alternately connecting and disconnecting an electrical power supply from a load. The disconnection device includes two spaced-apart terminals (2,4) having axially-aligned openings (6,10) and embedded in a non-conductive housing (34). A conductive pin (38) engages the openings (6,10) to electrically couple the terminals (2,4). The pin (38) has a handle (50) on one end thereof for locking or moving the pin (38) as needed. An elastomeric seal (64) between the handle (50) and the housing (34) protects the quick disconnection device from contamination.

Description: This invention relates to a compact electrical, quick disconnection device for high-voltage, high-amperage electrical systems such as are employed in electric vehicles, as specified in the preamble of claim 1. It is known to have electrical disconnection devices between high-amperage, high-voltage power supplies and the electrical loads they serve (see SU-A-609 138). It is particularly desirable to have such a device in a compact form in an electric vehicle to isolate a battery of the vehicle from electric drive and control systems of the vehicle, particularly during maintenance of such systems or of the battery. Disconnection devices used heretofore for high-amperage, high-voltage systems have typically utilised bulky manual switches housed in locked boxes. Such switches and the housings therefor are undesirable in applications, such as electric vehicles, where volume, weight and operating environment are important considerations. Any electrical disconnection device in an electric vehicle must not only have low mass and low volume, but must be simple to operate, essentially foolproof and capable of operating in an automotive environment which is subject to vibrations, corrosion and wide temperature variations. A compact, high-voltage, high-amperage, quick disconnection device according to the present invention is characterised by the features specified in the characterising portion of claim 1. It is an object of the present invention to provide a compact (ie, low volume/mass) high-voltage, high-amperage, simple to use, foolproof quick disconnection device which is capable of operating in an automotive environment. This and other objects and advantages of the present invention will become more readily apparent from the detailed description thereof which follows. This invention comprises a compact high-voltage, high-amperage quick disconnection device for alternately manually connecting and disconnecting an electrical power supply to/from an electrical load. The invention is particularly useful in electric vehicles, but may also be used in other applications. The quick disconnection device includes an input terminal receiving electrical current from an electric power supply, and an outlet terminal receiving electrical current from the input terminal for delivering it to an electrical load. The terminals are spaced apart from each other and each comprises an electrically-conductive sleeve embedded in an insulating material and defining an opening adapted to snugly receive therein a common electrical conductor which serves to electrically couple the terminals to each other. The terminals are held juxtaposed, albeit spaced apart, in an insulating housing such that the axes of their respective openings are aligned one with the other. A conductor whose external shape substantially conforms to the shape of the openings is movable in the direction of the axes of the openings for engaging and disengaging the sleeves to effect electrical coupling and uncoupling of the terminals. A non-conductive handle engages one end of the conductor for moving the conductor into and out of engagement with the sleeves. The conductor will preferably be a cylindrical copper rod. The sleeves, which are electrically connected to input and output cables, preferably comprise a bundle of parallel wires joined together at their ends and capable of expanding radially to snugly engage a conductor inserted therein. The wire bundle will preferably be necked-down at a location mid-way between the ends of the wires so that the sleeve has a generally hyperbolic, hour-glass shape. The necked-down portion of the sleeve is smaller than the outside diameter of the conductor but is readily expansible when the conductor is inserted therein. Once expanded, the sleeve will constrictively engage the outer surface of the conductor over substantially the entire length of the sleeve, hence resulting in a low-resistance electrical connection therebetween. Preferably, the wires comprising the sleeves are skewed with respect to the central axis of the sleeve with which they are associated so that the sleeve has a helical configuration. Most preferably, the wires are flat so that a large surface area thereof will engage the conductor for maximum low-resistance conductivity through the device. Such helical, hyperbolic connectors are per se known in the art, but have not heretofore been used in the manner described herein. The handle comprises a fingergrip portion and a flange portion overlying a substantial portion of the housing embedding the terminals. A collar depends from the flange, circumscribes one end of the conductor and mates with a well in the housing. At least one dog projects from the collar for engaging an undercut shelf in the housing adjacent the well upon insertion of the conductor into the sleeve and rotation of the handle so as to lock the conductor in position and prevent extraction thereof from the housing. The collar engages an auxiliary switch positioned in the housing for signalling or initiating other electrical disconnection devices, when the conductor is engaged or disengaged and hence the terminals are coupled or uncoupled with one another. The quick disconnection device will preferably include an elastomeric seal sandwiched between the flange on the handle and the upper surface of the housing to prevent incursion of contaminants (eg, dirt or moisture) into the housing and the terminals embedded therein. Most preferably, the perimeter of the seal will extend beyond the periphery of the housing and will engage the structure surrounding the housing for still further protection of the disconnection device from contamination. The present invention will be more readily understood when considered in the light of the following discussion of a certain specific example thereof which is given hereafter in conjunction with the accompanying drawings in which: Figure 1 is an exploded, isometric view of a quick disconnection device according to the present invention; Figure 2 is an isometric view of an underside of a handle and conductor assembly of the quick disconnection device shown in Figure 1; Figure 3 is a cross-sectional view of the handle and conductor assembly of Figure 2, taken in the direction 3-3 of Figure 2; Figure 4 is a partially-sectioned, isometric view of a helical, hyperbolic terminal sleeve used in the quick disconnection device of Figure 1; and Figure 5 is a cross-sectional view of a portion of the quick disconnection device of Figure 1, taken in the direction 5-5 of Figure 1. Figures 1 to 5 depict a compact, high current capacity (eg, ca. 400 amps continuous at 25°C), high-voltage (eg, ca. 500 volts) quick disconnection device including spaced-apart first terminal 2 and second terminal 4. The disconnection device is capable of handling ultra-high amperage excursions of about 2500 amps for 50-100 millisecs which is long enough for any fuses in a power circuit connected to the device to blow. The terminal 2 has an opening 6 therein defined by a sleeve 8. The terminal 4 has a similar opening 10 defined by a similar sleeve 12. The openings 6 and 10 are axially aligned with one another. The sleeves 8 and 12 preferably comprise a plurality of wires 14 separated by slots 16 which are joined together at the ends thereof by annular rings 18 and 20, as best shown in Figure 4. The end ring 18 of each sleeve is connected to a blade-like connector 22 which in turn is connected to a cable 24. A conducting cover 26 surrounds the sleeve 12 as best shown in Figure 4. The wires 14 will preferably be skewed relative to the centre axis of the respective openings 10 so as to provide a helical sleeve 8, 12. This is conveniently accomplished by twisting the respective sleeve 8, 12 which also causes the centre of the sleeve 8, 12 to become necked-down at a reduced diameter zone 28 and the sleeve 8, 12 thus takes on a hyperbolic, hour-glass shape. Terminals of this general type are known in the electrical connectors as hyperbolic or helical terminals. A preferred such terminal for this application is commercially available from the RADSOC Company, USA. The terminals 2 and 4 fit into respective conforming pockets 30 and 32 moulded into a housing 34 made of electrically-insulating material. The housing 34 is formed in two parts, 34a and 34b, which join together along the centre line of the terminals 2,4 to embed the terminals 2,4 completely therein. Appropriate fasteners (not shown) are provided to hold the housing halves 34a and 34b together. The housing 34 includes an opening 36 which is in axial alignment with the axes of the openings 6 and 10 in the terminals 2 and 4 and is sized to closely receive a conductor rod 38. The housing 34 includes a surface 40 having substantially concentric lands 42 and 44 thereon circumscribing the opening 36. The land 42 defines the mouth of a well 46 defined by an annular wall 47 and adapted to receive a collar 48 on a handle 50 attached to an end of the conductor 38. The collar 48 includes locking dogs 52 projecting radially therefrom which engage slots 54 in the wall 47. The bottom of each slot 54 opens to an undercut region 56 lying beneath a shelf 58 such that, upon clockwise rotation of the handle 50, the dogs 52 rotate under the shelf 58 and engage detent stops 60 in the underside of the shelf 58 to lock the handle 50 in place in the housing 34. To prevent unwanted counter-rotation thereof, a finger-like spring 61 is moulded into the housing 34 and serves to bias the respective dog 52 upwardly in the locked position behind the detent stop 60. To unlock the handle 50, downward pressure is applied thereto to depress the spring 61 sufficiently to permit the dog 52 to move beneath the detent stop 60 when the handle is rotated counter-clockwise. The handle 50 includes a flange portion 62 which overlies the lands 42 and 44 on the housing 34. An elastomeric seal 64 positioned between the handle flange 62 and the housing 34 is compressed between the flange 62 and lands 42 and 44 to provide a secure seal around the well 46. An upstanding lip 66 on the seal 64 engages the underside of the flange 62 to provide an additional seal. An upper flange 68 and a lower flange 69 on the periphery of the seal 64 extend radially outwards of the perimeter of the housing 34 and engage therebetween a body member of the vehicle which forms the mouth of a pocket (not shown) or the like in the vehicle in which the quick disconnection device is located for further protection from the elements. A lower inner flange on the seal 64 fits under a rim of the housing 34 to hold the seal 64 captive during the installation of the quick disconnection device to or in a vehicle. The conductor rod 38 comprises a highly conductive metal such as copper or alloys thereof and will preferably have a diameter of 10 mm or less. While the conductor 38 is preferably a cylindrical rod, other shapes may also be used. A cylindrical rod is preferred because it permits ready rotation of the rod and handle during locking and unlocking thereof and provides a continuous high surface area contact with the sleeves of the respective terminals 2 and 4. A switch 70 is mounted in the housing 34 so that a contact arm 72 thereof engages a lower rim 74 of the collar 48 when the conductor rod 38 is locked into place and serves (1) to signal whether or not the disconnection device is engaged or disengaged (and accordingly whether or not electrical power is connected to or disconnected from the load), and/or (2) initiate other electrical disconnection devices (eg, relays) which serve to further isolate the battery from electrical systems of the vehicle when the disconnection device is not locked in place. Upon insertion of the collar 48 into the well 46, the contact arm 72 is aligned with a cutout portion 53 on collar 48. Rotation of the handle 50 into the locking position causes a camming surface 55 to depress the contact arm 72 and close the switch 70. While the invention has been described primarily in terms of certain specific embodiments thereof, the scope of the invention is not intended to be limited solely thereto but rather only to the extent set forth hereafter in the scope of the claims which follow.

Claims: A compact, high-voltage, high-amperage, quick disconnection device for alternately connecting and disconnecting an electrical power supply to/from an electrical load, comprising an input terminal (2) for receiving electrical current from said supply, and an outlet terminal (4) for receiving electrical current from said input terminal (2) for delivering said current to said load, characterised in that said input terminal (2) has a first electrically-conductive sleeve (8) defining a first opening (6) adapted to snugly receive a rod-shaped electrical conductor (38), said opening (6) having a first axis; said outlet terminal (4) has a second electrically-conductive sleeve (12) defining a second opening (10) adapted to snugly receive said electrical conductor (38), said opening (10) having a second axis; an insulated housing (34) embeds said terminals (2,4) and holds them juxtaposed but apart from each other so that said first and second axes are aligned one with the other; the electrical conductor (38) conforms substantially to said openings (6,10) and is moveable in the direction of said axes for engaging and disengaging said sleeves (8,12) so as to electrically couple and uncouple said sleeves (8,12) to each other; and a non-conductive handle (50) engages said conductor (38) for moving said conductor (38) into and out of engagement with said sleeves (8,12). A disconnection device according to claim 1, in which said conductor (38) is substantially cylindrical in shape. A disconnection device according to claim 2, in which said sleeves (8,12) each comprise a bundle of parallel wires (14) joined together at both ends thereof. A disconnection device according to claim 3, in which said bundle of wires (14) is necked-down between said ends so that said sleeve (8,12) has a generally hyperbolic shape. A disconnection device according to claim 3, in which said wires (14) are skewed with respect to the axis of the associated sleeve (8,12) thereof so that said sleeve (8,12) has a helical configuration. A disconnection device according to claim 5, in which said wires (14) are flat wires. A disconnection device according to claim 3, in which each of said sleeves (8,12) expands upon insertion of said conductor (38) and constrictively engages said conductor (38). A disconnection device according to claim 1, in which said handle (50) includes at least one dog (52) engaging an undercut shelf (58) in said housing (34) upon insertion of said conductor (38) into said sleeves (8,12) and rotation of said handle (50) to lock said conductor (38) in position. A disconnection device according to claim 1, in which said housing (34) comprises a moulding formed of at least two parts (34a,34b) secured together at a parting line dissecting said terminals (2,4). A disconnection device according to claim 1, in which said conductor (38) comprises a copper rod. A disconnection device according to claim 1, in which said handle (50) comprises a collar (48) engaging said conductor (38). A disconnection device according to claim 11, in which said collar (48) includes at least one dog (52) engaging an undercut shelf (58) in said housing (34) upon insertion of said conductor (38) into said sleeves (8,12) and rotation of said handle (50) to lock said conductor (38) in position. A disconnection device according to claim 8, in which said housing (34) includes a detent (60) depending from said shelf (58) for preventing counter-rotation of said handle (50), and a spring (61) underlying said shelf (58), said spring (61) serving to bias said dog (52) into engagement with said shelf (58) when said dog (52) has been rotated past said detent (60) to thereby prevent unwanted counter-rotation of said handle (50). A disconnection device according to claim 13, in which said spring (61) has a finger-like configuration and is moulded integrally with said housing (34). A disconnection device according to claim 1, in which there is an elastomeric seal (64) positioned between said handle (50) and said housing (34) to keep contaminants from entering said housing (34); and there is a switch (70) in said housing (34) engaging said handle (50) for indicating the position of said handle (50) in said housing (34).

Inventors: HOLLIDAY REBECCA JO, RYBOLT ARNOLD CARL, SMITH GREGORY SHERWOOD, HOLLIDAY, REBECCA JO, RYBOLT, ARNOLD CARL, SMITH, GREGORY SHERWOOD
Applicants: GEN MOTORS CORP, GENERAL MOTORS CORPORATION
Application year: 1994
Main classification: H01R13
IPC codes: H01R13, H01H9, B60R16